I'm there right now. Gold treatment is very good. Went to front desk to check-in and the minute I presented my Gold card, he called a Concierge over who took me to his desk to check me in there.
Presented with the Spa pass and continental breakfast coupons, which he said were actually good for the full breakfast buffet. Without prompting, he inquired as to if I might need a bit extra time on my check-out date. He asked my flight time and said that he could extend check-out without charge to 3pm. He also upgraded me without prompting to the top floor (which is the only one with hi-speed internet, I gather).
Then escorted to my room, to be given the full tour of it's features.
Extremely nice treatment. I didn't have to do a thing but sit there and take what they offered, and Thank them.
Next time I would probably take a taxi instead of the comp hotel shuttle bus. After stopping at Terminal 1 it goes to Terminal 2 for a stop and load, and then also stops at the Excel Tokyu Hotel, before finally hitting the Hilton. Took 35 minutes from Terminal 1. Would have been another 30 minutes longer if the bus didn't happen to be sitting there when I arrived.